1. Field of the Invention
The present invention relates to a metal terminal to be installed on an electrical circuit substrate, and to an electrical circuit substrate on which such a terminal is installed.
2. Description of the Related Art
There is disclosed in Laid-Open Japanese Utility Model Application No. 63-72863 a metal terminal to be installed on an electrical circuit substrate. The metal terminal includes an elastic contact part, which is inserted into an installing hole of the circuit substrate and elastically contacts the inner peripheral surface of the installing hole, and a stop portion for preventing insertion of the metal terminal beyond a predetermined insertion position. When the metal terminal has been inserted, it is prevented to some extent from accidentally moving in the withdrawal (pull-out) direction by frictional resistance of the installing hole to the elastic contact part, and it is prevented from accidentally moving further in the insertion direction by the stop portion.
The terminal can be pulled out from the installing hole, for maintenance. However, there is no means for reliably preventing accidental movement of the terminal in the pull-out direction. Thus, it is impossible to completely prevent the accidental movement of the terminal in the insertion or pull-out direction. This can lead to the metal terminal making poor contact with the inner peripheral surface of the installing hole.
U.S. Pat. No. 2,755,453 discloses a metal terminal having a means for securely preventing accidental movement of the terminal in the pull-out direction. The terminal has a stop member for preventing insertion of the terminal beyond a predetermined position and a locking portion for preventing the terminal from being removed from the installing hole. The terminal is locked at one end of the installing hole by plastically deforming the locking portion when the terminal is stopped at the other end by the stop member. In this way pull-out of the terminal can be reliably prevented, and the terminal can be prevented from accidentally moving in either the insertion or the pull-out direction. However, it is difficult to restore the plastically deformed locking portion to its original shape. Thus, the terminal cannot be easily withdrawn for maintenance.